The invention described herein may be manufactured arid used by or for the government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
1. Field of the Invention
The present invention includes an explosive line charge. More particularly, high tenacity textile yarns are braided over individual explosive line charges to fix the position of the explosive charges in relation to each other with the covering of tubular braided material.
2. Brief Description of the Related Art
Connecting explosive charges in relation to each other is useful in explosive systems. This allows controlled sequenced explosions, when desired. Methods of connecting a number of explosive charges together are seen in current land mine clearing, shallow water mine clearing, and anti-personnel mine clearing explosive systems.
For connecting the explosive charges in the land mine clearing system, a nylon rope is sandwiched between blocks of explosive which are have been placed in a double pocket plastic bag and then skrapped with adhesive tape to hold them in place on the rope. The charges are then explosively connected to each other with two pieces of detonating cord which have been previously assembled onto the rope. The detonating cord transfers the detonation wave from one explosive charge to the next. This subassembly, of charges, rope, and detonating cord is slid into two lengths of hollow, woven tubular, nylon fabric sleeves. The explosive charges are held in place inside the fabric sleeves by tying short pieces of line around the outside of the fabric sleeves at the end of each charge. This, in theory, prevents the explosive charges from moving inside the fabric sleeves upon rocket launch, deceleration, or ground impact. The land mine clearing line charge method of connecting the charges has several limitations. Upon rocket launch, the charges slide around inside the fabric sleeves even though they are supposed to be held in place by the lines tied around the outside of the fabric sleeves. It is extremely difficult to tie the lines tight enough to prevent this motion. As a result, the charges end up in the back end of the fabric sleeves. This results in an uneven distribution of the explosive charges. In addition, on some occasions the acceleration forces are such that upon rocket launch some of the charges are expelled through the side of the fabric sleeves. Another disadvantage of this method of attachment is that there is a limited length of charges which can be inserted into the fabric sleeves.
In the shallow water mine clearing system, the explosive is housed in a thin metal container which is sandwiched between two aluminum flanges joined together with six bolt like pins. Each charge is connected to the next charge with two nylon webbings which are attached to the pins. The charges are connected explosively with a long piece of detonating cord that is inserted through the middle of the charges. The shallow water mine clearing method of attachment has severe limitations in that a great deal of weight must be added to the explosive charges to carry the rocket launch loads and acceleration. The weight of the flanges pins and webbing is a significant percentage of the overall weight and limits how far the rocket can launch the charges from the launch craft. In addition the metal parts such as the flange and the pins, which in the case of the shallow water mine clearing system weigh 504 pounds, pose a significant fragmentation hazard to the launch craft upon detonation. Finally, the cost of these parts represents a significant portion of the system cost.
The anti-personnel mine clearing method of connecting the explosive charges is to attach them to two nylon ropes by means of two metal band clamps which by means of friction, hold the charges to the ropes. The charges are explosively connected with a single piece of detonating cord that is inserted through the middle of the charges. The anti-personnel mine clearing method of connecting the explosive charges poses a hazard of the exposed hose clamps snagging during the deployment by the rocket motor. This method of assembly is also time consuming and prone to human error in the process of assembling the ropes to the charges.
The existing line charge systems, such as the land mine clearing, shallow water mine clearing, and anti-personnel mine clearing systems, connect the explosive charges together with either metal parts and ropes, webbing, or woven fabric sleeves. These methods of connecting the explosive charges makes the system expensive, heavy, and time consuming to assemble. Also the presence of metal components creates a fragmentation hazard to launch craft and personnel when the explosive line charge detonates.
There is a need in the art to provide a system for joining a number of explosive charges together into a line with a simple strong attachment system. The present invention addresses this and other needs.
The present invention includes a line explosive charge attaching system for connecting individual explosive charges in line comprising a yarn structure having a plurality of yarns interlocked in a braided structure capable of covering and positioning a plurality of individual explosive charges therein.
The present invention also includes a line explosive charge device comprising a plurality of individual explosive charges and a line explosive charge attaching system having a yarn structure braided over the plurality of individual explosive charges, the yarn structure having a plurality of yarns interlocked in a braided structure sufficient to position the plurality of individual explosive charges therein, wherein frictional forces between the plurality of individual explosive charges and yarn structure fix the position of the plurality of individual explosive charges in relation to each other.
Additionally the present invention includes a method for attaching a braiding structure to a plurality of individual explosive charges comprising the steps of positioning the explosive charges in the center of a braiding machine, initiating interweaving of yarn over the individual explosive charges with the braiding machine and calibrating the rate of interweaving with the feed rate of additional individual explosive charges to form a braid angle along the length between the individual explosive charges, wherein the plurality of yarns interlock into a braided structure sufficient to position the plurality of individual explosive charges in line therein.